test: add comprehensive TypeScript code extraction tests

[misrasaurabh1]

Summary

• Add comprehensive unit tests for TypeScript code extraction
• Verify that extracted TypeScript code is syntactically valid according to tree-sitter
• Test various TypeScript constructs including async functions, template literals, try-catch blocks

Context

While investigating issues where the API server returned "Invalid TypeScript: Invalid syntax" errors, we discovered that the local tree-sitter validation correctly validates the extracted code. This test suite documents the expected behavior and helps catch any regression in code extraction.

Test Coverage

The new tests cover:

• Syntax Validation: Basic functions, async functions, template literals, try-catch blocks, class methods
• Code Extraction: Simple functions, async functions with template literals, complex try-catch blocks
• Context Handling: Import statement preservation, global variable inclusion
• Language Properties: TypeScript language identification, file extensions, test file suffix

Test plan

• All 14 new tests pass
• Tests verify extracted code is syntactically valid
• Tests cover various TypeScript constructs that were reported as problematic

🤖 Generated with Claude Code